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<HR><A NAME=WIN32_task_1_inst>
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<H4>Subject: Ensuring only 1 copy of program running</H4><PRE>

In article <3usji6$fo7@news.midland.co.nz>, raymondg@talktech.co.nz says...
>
>
>I was wondering if anyone could tell me how to only run 1 instance of a 
>Windows program.  I understand about the hPrevInstance getting passed to the 
>new instance but how do I use this to activate the previous instance and make 
>sure the new instance isn't started (like what happens when you try to start a 
>second instance of clock.exe)?
>
>I am using Windows 3.1 and Borland C++ 4.02 and would appreciate any 
>suggestions, especially if anyone knows how to do this using OWL (2.0).
>
>Thanks
>
>Raymond
>
>raymondg@talktech.co.nz
>
>
>


hPrevInst will ALWAYS be 0 under NT. Try this instead:

HWND hWnd = FindWindow( "WindowClass", "WindowTitle" );
if ( hWnd )	{
	BringWindowToTop( GetLastActivePopup(hWnd) );
	return 0;
}


Cheers, Stefan
-- 
Stefan H. Holek, <holek@iv.co.at>

</PRE>

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<H4>Subject: Inter-application communication</H4><PRE>

In article <3vd6uq$5ks@news.asiaonline.net>, dion@asiaonline.net (Dion M Wiggins) writes:
|> Hi does anyone know of a good method to communicate between two 
|> applications running on the same machine under Windows 95. On NT you can 
|> use Named pipes, but Win 95 has a limitation in named pipes in that it 
|> will not allow you to create a "Client Side Server", that is you can only 
|> connect to a pipe, but can not create a pipe.
|> 
|> We can use DDE, but like many people I hate DDe, its a bad implementation 
|> in itself.
|> 
|> In Win 16, you can send messages to top level windows, which can trigger 
|> a real from memory map files or global attoms, but in Win 95, this does 
|> not work, as each app has its own ownership, and the messages are never 
|> recieved.
|> 
|> Presently we have had to resort to sockets (TCP/IP) and point to 
|> localserver. This is not a desireable solution as you must assume that 
|> the user has TCP/IP installed.
|> 
|> Any help appreciated.
|> 
|> Reagards
|> 
|> Dion wiggins
|> 
|> --

Use Anonymous Pipes

This should work, according to Documentation.
I am getting ready to do some of this work myself and this is how I plan
to do this task.  Someone out there could verify my plan and let me know
if I hhave it right.

Assume App 1 needs to read and App 2 needs to write.
App 1 creates the pipe using CreatePipe().
App 1 Gets a handle to App 2.
App 1 duplicates the write handle returned from CreatePipe() for App 2
	using DuplicateHandle().

App 1 sends App 2 the handle returned from DuplicateHandle using any other
	method, Windows message, shared memory, mail box etc.

App 1 closes the write handle returned from CreatePipe().

App 1 can now read from the pipe and App 2 can write the pipe.

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